[racket] Is there any particular reasons that Markdown-render does not deal with images?

> As the title says. Why?
>
> At least something like ![](already-exists-image-url) is neccessary.

Why:

1. I didn't know how.

At the time, I wasn't sure how to handle Scribble images generally.
And I wasn't aware of the special case you mention, that Scribble lets
you link to external image URLs. (Actually, does it? I don't know.)

2. It didn't seem important.

At the time, the new package system didn't have a way to host
documentation like PLaneT did. My motivation for doing this was that
it could help to generate README.md files for GitHub. (And none of the
package docs I looked at used images.) Anyway, these days
pkgs.racket-lang.org does now build and host full Scribble doc HTML.